A new genus of Corioxenidae, Malagasyxenos, is erected for a new species of Strepsiptera, Malagasyxenos gymnostoma n.s.p., from the Majunga provinces of Madagascar. Malagasyxenos is morphologically closest to Floridoxenos, both of which have antennae with seven segments and flabela on segments 3–6. However, Malagasyxenos is the only corioxenid with no visible mouthparts as well as other character differences. The family Corioxenidae is reviewed and a key is provided for the 13 genera.